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/*
* Hurl (https://hurl.dev)
* Copyright (C) 2025 Orange
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
use crate::reader::Reader;
/// Represent a parser error. This type of error ca be recoverable or not and
/// implements conversion to recoverable / non-recoverable instance.
pub trait ParseError {
/// Is this error recoverable or not?
fn is_recoverable(&self) -> bool;
/// Transforms this error to a recoverable one.
fn to_recoverable(self) -> Self;
/// Transforms this error to a non-recoverable one.
fn to_non_recoverable(self) -> Self;
}
/// A parser func.
pub type ParseFunc<T, E> = fn(&mut Reader) -> Result<T, E>;
/// Try to consume one instances of the provided parser.
pub fn optional<T, E>(f: ParseFunc<T, E>, reader: &mut Reader) -> Result<Option<T>, E>
where
E: ParseError,
{
let start = reader.cursor();
match f(reader) {
Ok(r) => Ok(Some(r)),
Err(e) => {
if e.is_recoverable() {
reader.seek(start);
Ok(None)
} else {
Err(e)
/// Makes an error recoverable but does not reset cursor.
pub fn recover<T, E>(f: ParseFunc<T, E>, reader: &mut Reader) -> Result<T, E>
Ok(r) => Ok(r),
Err(e) => Err(e.to_recoverable()),
/// Makes an error non recoverable.
pub fn non_recover<T, E>(f: ParseFunc<T, E>, reader: &mut Reader) -> Result<T, E>
Err(e) => Err(e.to_non_recoverable()),
/// Consumes zero or more instances of the provided parser.
pub fn zero_or_more<T, E>(f: ParseFunc<T, E>, reader: &mut Reader) -> Result<Vec<T>, E>
let mut v = Vec::new();
loop {
let initial_state = reader.cursor();
if reader.is_eof() {
return Ok(v);
Ok(r) => {
v.push(r);
return if e.is_recoverable() {
reader.seek(initial_state);
Ok(v)
};
/// Consumes one or more instances of the provided parser.
pub fn one_or_more<T, E>(f: ParseFunc<T, E>, reader: &mut Reader) -> Result<Vec<T>, E>
Ok(first) => {
let mut v = vec![first];
// if zero occurrence => should fail?
/// Tries to apply the list of parser until one of them succeeds.
/// Typically, this should be recoverable
pub fn choice<T, E>(fs: &[ParseFunc<T, E>], reader: &mut Reader) -> Result<T, E>
for (pos, f) in fs.iter().enumerate() {
if pos == fs.len() - 1 {
return f(reader);
Err(err) if err.is_recoverable() => {
continue;
x => return x,
unreachable!("You can't call choice with an empty vector of choice")